The present invention relates to firearm structure and more particularly to a small arms caliber reducing adaptor kit for reducing the caliber of an original barrel and an original cartridge chamber of a small arms piece. The novel features of the structure of the present invention permit its effective and ready adaptation to various types of small firearms such as pistols, revolvers, automatics, rifles and life firearms.
It is known in the firearms art to convert a firearm having a particular barrel bore caliber to one having a smaller caliber and to substitute cartridge chambers to correspond with smaller caliber barrels. U.S. Pat. No. 4,455,777, issued to D. G. Callies on June 26, 1984, teaches converting an original firearm barrel by inserting a smaller caliber insert therein and inserting a cylinder insert into an original cylinder chamber between the substitute barrel and the powder-receiving compartment of the original cylinder chamber, thus avoiding the need for substituting cylinder chambers. The cylinder insert in the structure disclosed in the Callies patent has a caliber corresponding to that of the substitute barrel but is comparatively complex in mechanical design, manufacture and assembly, requiring several moveable parts to permit its insertion into the original cylinder between the substitute barrel and the powder-receiving compartment of the original cylinder. It also is generally well known in the firearms art to utilize the principle of reducing barrel and cylinder bore of firearms so that the explosive charge can be reduced to permit practice shooting, target shooting and training and at the same time minimize dangers. U.S. Pat. No. 4,361,093, issued to M. E. Saxby on Nov. 30, 1982, discloses such arrangement, the Saxby structure utilizing a removable two part cartridge insert reloadable from the base. Like the aforementioned patent to Callies, the cartridge insert disclosed by Saxby is comparatively complex in design, manufacture and assembly, requiring several moveable parts including at least one or alternatively two removable inserts into the main cartridge insert to permit missile loading and securing through the base of the main cartridge insert.
The present invention recognizing the importance and desirability of providing a small arms caliber reducing adaptor kit for barrel and cartridge chamber so as to permit both accurate and economical target and training practice provides a novel structure which is economical and straightforward in manufacture and assembly. In addition, the structure of the present invention requires a minimum of parts and inserts, can be readily adapted for use with various types of small arms and can be reused and recharged in an efficient and economical manner, regardless of the nature of the original barrel or cartridge chamber bore of the firearm with which it is to be used, requiring a minimum of adjustment for barrel lengths and allowing a minimum of undesirable metal-to-metal contact in assembly and operation.
Various other features of the present invention will become obvious to one skilled in the art upon reading the disclosure set forth herein.